The present invention relates to means for allowing the disengagement of the transmission chain of a bicycle from the sprockets of the free wheel of the rear wheel, and the support of the same chain in the stretched position, with the possibility to be easily applied again on said sprockets.
The object of the present invention is to facilitate the operations of mounting and removal of the rear wheel of a bicycle preventing, during removal, the total disorderly collapse of the rear part of the chain onto the derailleur of the speed-change gear and the difficulties in the subsequent mounting on the driving sprockets of the rear wheel. Such drawbacks are now present in all the bicycles and they are particularly felt by the cyclists who use their bicycle for sporting purposes or who actually take part in contests or races, but they also disturb the common user and the bicycle mechanic, who have to soil their hands, work hard and waste time on an operation which would be much simpler and quicker if it could be performed with the chain in a stretched position, anchored to the bicycle frame.
The above problem is very simply and efficiently solved by the present invention which provides, on the one hand, means for guiding and supporting the chain, associated to the frame and more precisely to the rear fork of the bicycle, and on the other hand, improved means for controlling the bicycle speed-change gear, in order to operate the deviation of the chain on said guiding and supporting means.